Tool holder



Oct. 18, 1932. c. B. GRAY TOOL HOLDER Filled Nov. 25. 1930 ATTORNEY Patented Oct. 18, 1932 cnAnLes B. GRAY, or MILLBOURNE, .PENNSYLVANIA PATENT OFFICE TOOL HOLDER.

vAppiication flied-November 25,A 1930. Yserial* No'.497,9ss.

My invention relatesto cutting machines of the punch type having a reciprocatory ram and a tool and it has for an Aobject to provide improved connections between the ram 51 and the tool adequate for the transmission of cutting stress to the tool, for stripping the tool from work, for positively centering the cutting end of the tool, and for axial adjustlmentofthe tool with respect tothe ram.

In accordance with my invention, the ram,

or ram construction, is provided with an axial bore within which is disposed the punch tool.

Abutment means is arranged in the bore and abuts the top of the tool, and such meansis adjustable to takecare of variation in tool length. On its working stroke, thrust is j transmitted fromA the ram,through lthe ading means iitting the ram bore and serving Theseand other objects are eii'ected by myf saryfto strip the tool from the stock.

I'this end,'the sleeveV 17 is held in place with justable abutment means', to the top of the tool. A separate connection is provided be tween the rain and the tool so that the latter 'may be stripped from stock on back strokes.

The shank of the tool is surrounded by Aspacto resist buckling of the tool. Acentering die even though the tool is turned about its aXis. A further object of my inventionis to provide an improved ram and tool connection construction having these advantageous features.

invention as will be apparent vfrom the following speciii-cation taken in connection with the accompanying drawing vin which Fig. l is a sectional view of my improved constructionl showing the tool in elevation;

Fig. 2 is a sectional view rvshowinga modified form Figs'. 3 to 10, inclusive, are sectionalviews:

pshowing fiirthermodiiied forms wherein'the tools are provided with heads;-v

Fig. 11 is a sectional viewof a modied construction somewhat .likeV Fig. 1;.

Fig; 12 is a Ysectional view showing a Vfurther modied'form of head construction.;v

Y Fig. 13 is a sectionalview showing a ram .construction including anadapterg f l Figs. 14 and 15 are detail views of the collet 4 used with'the construction of Fig. 13; and

Figs. 16, 17 and18 are detailviews of an improved tool.

tail, in Fig. 1, 1 show a ram 10 having an axial Vbore 11 provided with an upper abutment 12. A punch tool-13 is disposed within the bore. Adjustable spacing meansjis also disposed within the bore, such spacing means where the cutting end of the tool is sharp ened or dressed. To this end, in'F ig. 1,'a

t sleeve 17 fits within the bore 11 and the sleeve is provided with a bore 18 within which is Varranged the tool. @ne or `more-'spacing members 20,for example, one, are arranged in the bore 18 lbetween the Aupper end 16 of the tool and a backing screw 21 threaded in the upper end or the bore as shown at22. The backing screw 21 is split and has an eX- device is provided at the lower end of the pansion 'screw 24 for .locking the backing ram to assure alinenient of the tool with the screw. in adjusted position;

Referringy nowto the drawing more in de- Y length, this being particularly desirable On working strokes, thrust is transmitted from the Vram abutment, through the adjustable spacing means, including the sleeve 17, the backing screw 21 'and the spacer20, to the top of the tool 13. Y

On back strokes of the ram 10, it isnecesits upper end '1 4 pressed 'against the abu t' and an V ipening26, respectively, which-com? pleinentally form an Opening for the tangent stripping pin o rjkey 27.v To provide for kaxial adjustment of thetool lrelative to the sleeve 17,.the latter is provided with a..

plurality oi' staggered openings 26 with any e.

of which the notch25 maybe caused to register. l

Collet mechanism, at 28, iscarried by the lower end or' the vram` and itl serves'to hold the sleeve 17 in place under compression Vment 12 by Y'colletV mechanism, hereinafter" referred to, and the sleeveisconnected to y'the upper Vportion of the Atoolat one` side,

the tool and the sleeve having a notch 25 and to center the cutting end of the tool 13. The collet mechanism includes a nut threaded to the ram at 31, and the nut has an opening 32 within which is arranged the lower portion of the colletl 33 so that the nut engages underneath the collet shoulder 34. The collet 33 has a bore 35 for the tool 13 and it is split, as shown at 36. The Vupwardly-tapering, external, conical surface 37 of the collet lits within the internal conical surface 38 of the split ring 39 having an external cylindrical surface 40 for expansion against the ram bore wall and having an upper abutment surface 41 engaging the lower abutment surfaceY 42 of the sleeve 17. As the nut 30 is screwed up, the split ring 39 is moved up to cause the pairs of abutm-ent surfaces 41, 42 and 14, 12 to engage under pressure; and then, with axial movement of the ring 39 arrested on this account, the collet 34 causes the ring to expand to lit tightly within the ram bore. As the internal conical surface 38 is coaxial with the external cylindrical surface Y40 and, therefore, with the ram, and as the external conical surface 37 of the collet is coaxial with the bore thereof, continued tightening of the nut 30 results in centering of the lower end of the tool and gripping thereof.

Onl back strokes of the ram 10, stress is f transmitted from the ram, through the collet mechanism at v28, to the sleeve 17, and from o the latter, through the stripping pin 27, to

vthe tool 13 to strip the latter from stock. rIhe top of the tool is bevelled at 43 above the strippingpin notch`25 so thatthrust is exerted back of the notch and on a straight line to the cutting end'of the tool. Vithout the bevel, a part of the thrust would be overVV the notch and the moment arm over the stripping pin would tend to cause breakage of the tool at the notch because of pressure on 'the portion overhanging the stripping pin and the notched portion being the weakest section of the tool. The bevel avoids such pressure effects.

A screw 44 is preferably carried by the ram to hold the sleeve 17 against turning incidentV to tightening of the collet mechanism.

The ram construction of Fig. 1, therefore, transmits working thrust or stress from the abutment 12, through the adjustable spacing means, to the top of the tool; and stripping stress is transmitted from the ram and the connected collet mechanism, at 28, to the sleeve 17, and, from the latter, through the stripping pin, to the upper portion of the tool. The staggered openings 26 in the sleeve provide for axial adjustment of the tool, spacing means 20 of suitable lengt-h being provided'and the backing screw 21 being screwed down to remove all looseness. The sleeve 17V also functions 'as spacing means between the ram bore and the tool to pre-.

vent bucklingof thelatter on working or upwardly-tapering,

face 37 fitting the surface 38a, the collet coni-` cutting strokes. The collet mechanism serves not only to remove any looseness or end-play of the sleeve 17 with respect to the ram but also to center land to grip the lower` portion of the tool. ylhese features provide adequate stress transmitting connections, centering of the cutting end of the-tool, and the location of the cutting end of the tool quite close to the lower end of the ram, the latter result being important in that the tool overhang with respect to the ram or the column length below the ram is minimized to give maximum tool strength and avoid deflection.

Fig.- 2-is similar to Fig. 1 except that the spacing means is formed separately from the holder or sleeve 17 a and the collect mechanism is slightly different. The spacing means is comprised by the sleeve 46, formed separately from and spaced a short distance above the tool sleeve or holder 17 a, the back-v ing screw 21a threaded to the sleeve 46, and the spacer or spacers 2O of suitable length. The upper end surface 14a of the sleeve 46 abuts the ram abutment 12. The spacer 20U upwardly-tapering, internal conical surface 38a, which is coaxial with the cylindrical surface of the sleeve 17a and with Vthe -ram and the bore 11 of the latter. The collet 34 has external conical Vsurcal surface being coaxial with its bore 35. As the collet nut 30 is screwed up, thrust is first transmitted from the conical surface 37 to the conical surface 38a, causing the sleeve 17 a and the too] 13 to move up sufficiently for ,Y the top surface 15 of the tool to abut with the abutment surface 16 of the spacing means,

the spacer 20 abutting the backing screw 21a and the latter causing the sleeve46 to abut with the ram abut-ment l2. After all play is taken up in this way,'continued screwing up of the nut 3() results in centering and gripping of the lowerend ofthetool. If the Vthreads of the sleeve 46 should be stripped, such sleeve can be replaced without making it necessary to replace-the sleeve 17a provided with the staggered openings for the stripping Vpin and with the lower conical surface.V

ln Fig. 3, l sho-W a further modified form of my invention wherein the A adjustable` spacing means is arranged between. the ram abutment 12 and the top surface of the tool, axial adjustment being secured by operating the backing screw; 21?). A tool holder or head 47 is connected to the backing screw and`V to the upper'end of the tool 13a, the holderv o-r head 47 having upperL and lower bores 48 and 49 having arranged thereinthe lower end of the backing vscrew and the vupperend` of the tool, respectively. Tangent pinsor key/S50y and 51connect the backing screw and the tool to the holder or head. Washers 52 of vari- Q able thickness fitting about the tool 13a and within the ram bore are arranged between the holder or head and the collet mechanism.

As the holder or head 47 is formed separately from `the tool, manufacture of the latter, parl ticularly grinding of the latter from round nut 30a having a downwardly-tapering, internal conical surface 53 fitting the down-` wardly-tapering, external conical surface 54 stock, is simplified. n

The collect mechanism of Fig. 3 includes a of the collet 34a. The collet lnut 30a has an internal cylindrical surface 56r coaxial with L Athe conical surface 53 and litting the ram cylindrical surface 55. Y V

Asthe collet nut 30a is screwedrup, the

'i collet 34a is caused to abut thelowermost washer 52' and thrust is transmitted through the washers to the holder or head 47,v from the latter to the backing screw 215, from the backing screw to the sleeev 46a, and-from the latter to the ram abutment 12, whereby all looseness or end-playis taken out.- Adjustment of the tool relatively to the rain is provided for by choice of washers 52 so thatthe tooldepends below the yram to a desired extent, and the sleeve 46a is adjusted along thebacking screw suitably to the length of tool.

On, working strokes ofy the ram, thrustis transmitted from the ram abutment, through the adjustable spacing means, to the top ofv the tool; and, on back strokes of the ram',`Y

stress is transmitted from'the ram to the collet mechanism, through the spacing washers to the head or holder 47, and'from the latter through the stripping pin 51. to. the tool. As before, the collet mechanism also centersl and grips the lower portion of the tool, theV coaxial conical and cylindrical surfaces 53, 54, 55, and 56 assuring centering. f

In Fig. 5, the .ram 10 is provided with a A threaded bore 11a and modified adjustable spacing means is arranged between the top of the tool 13a and the ram, the spacing means consisting of a head or holder 47 a threaded tothe borella, having a lower bore 49a receiving the upper end of the tool, and being connected to the --upper portion of the toolv by the stripping pin 51a. Floating washers 57 are arranged about the tool and in the ram bore to resist buckling of the tool. A collet nut 305 is threaded to the lowerend of the ram, engaging Ycylindrical centering or pilotV Y surfaces 55 andV 56 are provided on the ram and the nut, downwardly-tapering conical surfaces 53a and l540i-are provided :on thenut 305 and the collet 345, respectively, and the collet has an abutment shoulder 58engaging.

the lower end of the ram. TheV cylindrical surfaces 55 and 56 of the ram and the collet Vnut and the'conicalsurface 53a of thenut are'coaXial with' the ram, the conical surface 54a and the bore 35 ofthe collet 345 are coaxial, andthe tool is disposed in the collet bore, whereby, when the collet nut 305 is and the headandv tool assembly is prevented .from turning in the ram bore.

` lIn Figs. 8 and 9, a head or holder 475 is Y Varranged in the ram bore and it is connected vscrewed up, the tool is centered and gripped to the tool 13a and to a rod 62 by the keys or pins`51 andl 50a, respectively, and adjustment is secured byplacing washers 61 of.

suitable thicknesses below the head (Fig. 9), aboveV the head, ror both above and below the lhead (Fig. 8) depending on the tool length.

When the length of the tool is a maximum, all of the washers 61 are arranged below the head, as shown in Fig. 9; and, as the tool is shortened due to sharpening, washers are removed from below the head and placed thereabove (Fig. 8) until finally, with the shortest tool length, all the washers are located above the head. The collet nut serves, as heretofore, to remove end play and then to center and grip the lowervportion of the tool.

Fig.' 10 is somewhat like Fig. 3, except that the holder or head 47 c of Fig. 10 is provided witha bore 495V which accommodates both the upper portion of the tool and the lower portion of the spacer 63, the upper end of the latter engaging the ram abutment 12a.. In

this form, adj ustably spacing of the tool relatively to the ram 'abutment is secured by the use of a spacer or spacers 63 of suitable length.

Fig. 11 is similar to Fig. '1, except for modi- Y lication of the collet mechanism. 'In Fig. 11,y

the lower end of the collet 330 is downwardly- Y tapered at 6 4 Vand the sleeve or ring 39a has a `downwardly-tapering, internal conical surface 65 litting the surface 64 and an external cylindrical surface l66 iitting the interior of ram constitute a ramrconstruction in this modification, since the adapter is virtually a partofvtheram, and the term cram construction is used herein in a general sense to' refer to a ram with or without an adapter.

' The adapter 70 has a bore 1,15 within which y is arranged a sleeve 175 connected to the tool llO as in' Figs. 1 and 2. The upper end of the Y the abutment and adjustable spacing -means 63a contacts with the upper end of the tool, protrudes from the upper end of the sleeve, and contacts with the abutment 125. The collet mechanism is similar to that shown in Fig. 3 except that vthe collet nut 300 has a roundedinterior annular surface 73 engaging Asleeve is spaced a short distance from' l Athe external, downwardly-tapering conical surface 54o of the collet 34d.

ln'Figs. 16, 17 and 18, l show mypreferred forni of punch tool suitable for nibble cutting. The cutting edge 74 is approximately semicircular 18). A depending pilot 75 is disposed back of the cutting edge 74 and it is reduced in cross-section downwardly in order to obtain more proficient performance with harder and tougher alloys now being produced. This form of pilot is produced by removal of stock for a suitable length and far enough back of the center of the round section to provide for progressive overlapping of the cutting edge of the tool with respect to ,stock being cut. Overlapping feed is limited I by the edges 75 of the pilot contacting with a previous semi-circular cut. rllhe front face of the pilot is spaced backwardly with respect to the cutting edge so that room is allowed for the spread of a slug under pressure of the cutting action so that the slug will not bear on the pilot front face with such force as to cause gripping between the slug and the pilot and crowding ofthe tool excessively against the die or over the cutting edge' of the die. The sides .6 of the pilot are tapered downwardly to provide for freeing of the pilot more readily'if 4a slug should spread and wedge between the pilot and the die. Furthermore, the tapered sides provide more room for slug spreading at the sides. On tip-strokes, the tool picks the stock up until the latter reaches the stripper7 and the stock may tip so that one side is higher than the other, in which case, if a straight-sided pilot is used, excessive gripping of the pilot on account of friction may take place with the result that, as the pilot is of weaker section than the tool, it may be broken olf. 0n the other hand.. with a pilothaving tapered sides, even though the stock should tilt, the sides of the ke'rf would not tend to grip but the pilot tends to release itself. This feature is of importance particularly where cutting tough and sticky alloys which tend to stick or gald to the tool or pilot. A tool having these features of construction is more particularly disclosed and claimed in my application Serial No. M5310, filed July 2, 1930.

From the foregoing, it will be apparent t iat l have provided an improved ram and tool construction particularly suitable for a nibbling` machine. @n working strokes, thrust is transmitted' from the ram, through spacing means, to the top of the tool.. Separate means including collet mechanism and a stripping pin connection serves to transmit stress from the ram to the tool to strip the latter from stock; and the collet mechanism-also serves to secure pressure contact of the abutting surfaces which are active in transmitting working or cutting thrust to the tool. 1n. addition the collet mechanism provides for centering and gripping' of the lower end of the tool to assure alinement thereof with the die. Bevelling of the top of the tool above the stripping pin minimizes the possibility of breakage of the tool at the pin notch. The tool is reinforced throughout the length thereof in the ram against buckling. 'The tool may be readily disconnected for replacement or dressing, the spacing means being adjustable to properly position the cut-ting end. Furthermore, the cutting end of the tool may be located quite close to the lower end of the ram, thereby minimizing the tool overhang and the possibility of deflection 'thereof below the ram. i i

1What l claim is: Y

1. 1n a cutting machine of the reciprocatory punch type, a ram construction having an axial bore, a punch tool in the bore,abut ment means in the bore'and vabutting the thrust end of the tool and operatively connected to the ram construction for transmitting working thrust vfrom the iatterto the thrust end of the tool, means providing for axial adjustment of said abutment means suitably to the tool length, means providing a connection between the ram construction and the tool for stripping the. latter from work, collet mechanism carried by the lower end of the rain construction for gripping and centering the tool, said mechanism including a collet disposed about the tool and having an external conical surfaceand means for contracting the collet including" an annularv member having a surface engaging the conical surface of the collet and coaxial with an annular member cylindrical lsurface engaging a cylindrical surface formed on the ram construction and coaxial with the latter, and spacing means encompassing the tool between the stripping connection and the'collet and fitting the bore to resist buckling ofthe tool in the bore.

2. 1n a cutting machine of the reciprocatory punch type, a ram construction having an axial bore, a punch tool in the bore, abutment means in the bore and abutting the upperend of the tooly and operatively connected to the ram construction for transmitting thrust from the latter to the tool, means providing for axial adjustment of said abutment means suitably to the tool length, a notch formed in the tool adjacent to the upper end, a key carriedv by the ram construction and engaging in said notch, the top end of the tool being bevelled directly above Vthe' notch to relieve the portion of the tool between the notch and the upper end from thrust stress, collet mechanism carried-by the lower end of the ram construction for gripping and centering the tool, said mechanism including a collet disposed about the tool and having an external conical surface and means for contracting'V the collet including an jannular member having a surfaceengaging thek conical surface of the collet and coaxial with an annular member cylindrical surface engaging a cylindrical surface formed on the ram construction and coaxial with the latter,

its upper end', a tool in the' bore and havingL an upper thrust abutment end, spacing means in the bore and having an uppenabutment engaging the ram construction abutment and a lower abutment engaging the tool thrust abutment, means providing for adjustment of the spacing means to vary the distance between its upper and lower .abutments, collet mechanism carried by the lower end of the ram construction for gripping and centering the lower end of the tool.I said mechanism including a collet ydisposed about the tool and having an external conical surface and means for contracting the collet including an annular member having a surface engaging the conical surface of thel collet and coaxial with an annular member cylindrical surface engaging a cylindrical surface formed on the ram construction and coaxial with the latter,

a stripping connection between the ram conbore provided with a downwardly-facing abutment, a tool in the bore, adjustable spacing means between the tool and said abutment and including a sleeve abutting said abutment and a. screw threaded in the sleeve for transmitting thrust from the ram construction to the tool, collet mechanism carried by the lower end of the rain construction for gripping and centering the lower end portion' of the tool, said mechanism including a collet disposed about the tool and having an external conical surface and means for con: tracting the collet including an annular mem ber having a surface engaging the conical surface of the collet and coaxial with an annular member cylindrical surface engaging a cylindrical surface formed on the ram construction and coaxial with the latter, a stripping connection between the upper end portion of the tool and the ram construction, and spacing means encompassing the tool between the stripping connection and the collet mechanism and fitting the boie to resist buckling of the tool in the bore.

5. |llhe combination as claimed in claim l with spacing means between the top of the tool and the bottom end of the screw.

6. The combination as claimed in claim 4L withv means responsive to tightening of thev collet mechanism to cause the sleeve to abut the boreV abutment under pressure.

A17. In a cutting machine of the reciproca-V tory type, a ram construction having an axial bore with a downwardly-facing abutment at its upper end a tool in the bore and having an lupper thrust abutment; a sleeve fitting the bore, abutting said abutment, and having a bore coaxial with the ram construction for said tool; ,tool abutment means in the sleeve and including a backing screw; means'for connectingthe tool to the sleeve including` aplurality of openings distributedv longitudinally of the sleeve and a notch in the tool Y adapted to be registered with any one of the openings and al pin arranged to fit anvopening and the notch when in registry; collet mechanism carried by the lower end ofthe rain construction for urging the sleeveA 'against the ram bore abutment and centering engagihg the conical surface of the collet andA coaxial with anv annular member cylindrical surface engaging av cylindrical surface formed onlthe ram construction and coaxial with the latter, and spacing means encompassing the tool between the stripping connection and the collet mechanism and fitting the bore to resist buckling of the tool in the bore..

8.`ln a cutting machine of the-recipro-` catory type a ram construction Vhaving an axial bore with a downwardly-facing abutment at its upper end, a sleeve fitting `the bore and having a bore coaxial with the ram construction and its bore, the upper end of the sleeve being spaced from the rain bore abutment, a tool in the sleeve bore, means for connecting the tool to the sleeve including a plurality of transverse openings distributed longitudinally of the sleeve and a notch in the tool adaped to be registered with any one of the openings and a transverse pin arranged to fit an opening and the notch when inregistry, spacing means disposed in the sleeve bore and engaging said ram bore abutment and the tcp of the tool, collet mechanism carried by the lower end of the ram construction for centering and gripping the lower end of the tool, said mechanism including a collet disposed about the tool and having an external conical surface and means for contracting tre collet including an annular member having a Vsurface engaging the conical sur` face of the collet and coaxial with an annular member cylindrical surface engaging a cylindrical surface formed on the ram construction and coaxial with the latter, and spacing means encompassing the tool between the stripping connection and the collet mechanism and fitting the bore to resist buckling of the tool in the bore.

9. In a cutting machine of the reciproca-A tory type, a ram construct-ion having a bore,

a tool in the bore and provided witha head at its upper end, means for transmitting thrust `from the ram construction to the upper end of the tool and' providing for adjustment of the tool axially of the bore, collet mechanism carried by the lower end of the ram construction for gripping and centering the lower end of the tool, and spacing means fitting the bore between the head and the collet mechanism and fitting the tool shank to resist buckling of the latter.

10. The combination as claimed in claim 9 wherein the thrust transmitting means embodies adjustable spacing means and the spacing means between the head and the collet mechanism is adjustable.

11. The combination as claimed in claim 9 wherein the means for transmitting thrust from the ram construction to the upper end of the tool embodies a plurality of superposed washers and the spacing means between the head and the collet mechanism also embodies a plurality of superposed washers.

12. In a cutting machine, a ram, a punch tool, cutting stroke connecting means between the ram and the tool including` an abutment engaging the top end of the tool and subjecting the latter to compressive stress on cutting strokes, and stripping connecting means between the ram and the tool including complementary recesses formed in the tool and in an element carried by the ram and a pin ein gaging in the complementary recesses, the top end of the tool being relieved above the recess therein so that the portion of the tool above the recess is not subjected to compressive stress on cutting strokes.

In testimony whereof, I have hereunto sub scribed my name this 20th day 0f Nov. 1930. CHARLES B. GRAY.

DISCLAIMER 1,883,713.Oharles B. Gray, Millbourne, Pa. TOOL HOLDER. Patent dated October 18, 1932. Disclaimer iled April 27, 1938, by the patentee.

Hereby disclaims from claims 9, 10, and 11 all tools of the headed type, said claims being hereby restricted to tools of substantially uniform cross sectional area from end to end, except for limited portions of smaller area, a respect to stripping sleeves, the telescoping portions of the tools and of the sleeves having lateral stripping connections and the ends of the tools remote from the cutting ends providing cutting thrust abutment surfaces.

{Ojjcal Gazette May 30, 1933.]

nd telescopically arranged with 

